The present invention relates to improvements in vapor recovery fuel dispensers and specifically with an improved mechanism for actuating a valve in the vapor line of a vapor recovery fuel dispenser.
Although vapor recovery fuel dispensers have been known for a number of years, progress continues to be made in improving the ease of use, efficiency and economy of such fuel dispensers. A particularly advantageous advance in this field was the VaporVac.TM. Vapor Recovery Fuel Dispenser marketed by Gilbarco, Inc., of Greensboro, N.C. In the VapoNac.TM. line of fuel dispensers, a vapor pump is provided in the vapor return line to draw vapor into the system as it is displaced from an automobile fuel tank as liquid fuel is dispensed into the tank through a nozzle. The nozzle is provided with openings into which the vapor passes under the influence of the vapor pump, and the vapor is directed to underground storage tanks to occupy the volume displaced by the liquid being pumped therefrom.
In one commercial embodiment of the VapoNac.TM. product, multiple hoses are used on a single dispenser, each having its own vapor return line. Solenoid valves in each vapor return line in the dispenser are normally closed, but one is opened when its associated vapor line is to be activated. Down stream of the solenoid valves, the multiple vapor lines are merged together in a manifolded fashion so that only one vapor pump is needed. Providing the solenoid valves assures that the vapor being pumped comes from the active hose. It also prevents the escape of vapor during idle periods.
Also known is the provision of multiple hoses having vapor valves located in the nozzles, as taught in U.S. Pat. No. 5,195,564 to Spalding. However, in the case of both the VaporVac.TM. solenoid valves and the Spalding nozzle-located valves, there are certain disadvantages. Solenoid valves are rather expensive, and it would be advantageous if their use could be avoided. Similarly, the nozzle-located valves experience short life-times requiring high replacement cost because the nozzles in which they are located are subject to exposure to the elements and to abuse. Since the valve is located in the nozzle, replacement of either requires replacement of the other, even if replacement is not needed.
Accordingly, there is a need in the art for an improved valve for a vapor return line and a vapor recovery fuel dispenser.